*{
    font-family: "Microsoft JhengHei", 微软雅黑;
}
html{
    background-color: #baedfa;
}
h1{
    text-align: center;
}
h2.problem{
    padding:5px;
    color: red;
    border:3px solid #ff7500;
    background-color: yellow;
}
h3:before{
    content: "—— ";
    /*font-weight: bold;*/
}
h3:after{
    content: " ——";
}
h3{
    padding:5px 10px;
    font-family: 微软雅黑;
    font-weight: normal;
    background-color: lightgreen;
}
h3 span{
    padding:1px 5px;
    font-family: "Microsoft YaHei UI", sans-serif;
    font-weight: bold;
    background-color: yellow;
}
body{
    padding: 0 10% 5em;
}
@media screen and (max-width: 639px){
    body{
        padding: 0 0 5em;
    }

    div:not(#menu):not(.subMenu){
        box-sizing: border-box;
        margin: 10px auto !important;
    }
    code{
        margin-left: 2px !important;
        white-space:  pre-line!important;
    }
}
button{
    display: inline-block;
    margin:5px;
    border-radius: 3px;
    color: white;
    background: #00c400;
}

code{
    display: inline-block;
    margin: 3px 0 5px 10px;
    font-family: Consolas;
    padding:1px 5px;
    white-space:pre;
    color: #6058c9;
    border:1px solid crimson;
    background: #ceebc0;
}
strong{
    font-family:  "Adobe Fan Heiti Std B";
}


/*悬浮的导航*/
 #menu{
     position: fixed;
     bottom: 4em;
     left:-20.7em;
     width: 19em;
     height: auto;
     padding: 15px;
     z-index: 10;
     border-radius: 15px;
     box-shadow: 1px 1px 5px 3px black;
     background-color: rgb(237, 255, 202);
     transition: left 0.5s ease ;
     /*transition-delay: 0.4s;*/
 }

#menu:hover{
    left:0;
    transition-delay:0s;/*鼠标移上时快速移动，移开时缓慢返回*/
}
#menu h1{
    margin-top: 0;
    margin-bottom: 5px;
}
#menu section{

}
#menu h2{
    cursor: pointer;
    margin:3px auto;
    counter-increment: mycounter;
    counter-reset: mysubcounter;
    padding-left: 10px;
    font-size: 1em;
    font-weight: bold;
    text-shadow: 1px 1px 1px darkgray;
    color: #191919;
    background-color: rgba(146, 230, 169, 0.61);
}
#menu h2:hover{
    color: #caffe3;
    background-color: #698005;
    text-shadow: 1px 1px 1px black;
}
#menu h2:before{
    content: "—第"counter(mycounter)"章 ";
    font-weight: bold;
    /*font-size: 1.8em;*/
}
#menu h2:after{
    content: "—";
    font-weight: bold;
}
#menu section a{
    counter-increment: mysubcounter;
    display: block;
    padding-left: 10px;
    margin: 3px 2em;
    /*font-family:  华文宋体, 宋体, serif;*/
    font-size: .8em;
    font-weight: bold;
    text-decoration: none;
    /*text-shadow: 1px 1px 1px darkgray;*/
    color: #002772;
    /*background-color: #a8e2f6;*/
}
#menu section a:before{
    font-size: 1em;
    content: "☞ 第"counter(mysubcounter)"节 ";
    font-weight: bold;
}
#menu section a:after{
    content: "";
    font-weight: bold;
}
#menu section a:visited{
    text-shadow:1px 1px 1px gray;
    color: #666;
}
#menu section a:hover{
    text-decoration:underline;
}
#menu h1{/*浮出的导航文字*/
    position: absolute;
    width:1em;
    right: -1em;
    bottom: 0;
    font-size: 1.5em;
    color: blue;
    border:1px solid blue;
    border-radius: 5px;
    background-color: rgba(255, 255, 0, 0.81);
    opacity: .7;
}
@media screen and (max-width: 640px) {
    #menu {
        width: 16em;
        left:-17.5em;
        padding:10px;
    }
    h1{
        margin: -5px;
    }
    #menu h1{
        font-size: 1em;
    }
    #menu h2{
        font-size: .8em;
        text-shadow: none;
    }
}
